Transmitter for selective signaling systems.



V. DURBIN. TRANSMITTER FOR SELECTIVE SIGNALING SYSTEMS. APPLICATION FILED 0017,1910.

1 53,584, Patented Feb. 18, 1913.

4 SHEETS-SHEET 1. l

V. DURBIN.

TRANSMITTER FOR SELECTIVE SIGNALING SYSTEMS APPLIOATION FILED OCT. 7, 1910. I

Patented Feb. 18, 1913.

4 SHEETS-SHEL'T 2.

WEQ a Patented Feb. 18, 1913.

4 BHEET8-BHEET 3.

v v. DURBIN. TRANSMITTER FOR SELECTIVE SIGNALING SYSTEMS.

" APPLICATION FILED 0017,1910. Patented Feb. 18, 1910.

-- phone-systanm.

U lTEl) @TATEhl lhidllfilflll? @FlillQE sacnvsmrs. I

VERNON DURBIN. OF 'BROOKLINE, IlIiSSAUl-iUSET'IS, ASE,

ELECI'RIC COMIPANY. F BRQOKLINE. MASSA IGNOR T0 HOL'IZEB-CABOT GIEIUSETTCS'. A CORIORATION 0F MAS- TRANSMITTER FOR SELECTIVE SIGNALING SYSTEMS.

.Mginal-application 111ml May 16, 1910, Serial No. 561.645.

Specification of Letters Patent.

' 191.0. Serial No. 5815808.

torilelective Sigmlling; Systems. of whivh the following is a :anwification.

My invention relates: to transmittal-a for; selective iilgl'lilllflg systems adapted for usv IHOIE'OSPQKZifillY in train-(lespatolnng tale- The primary object of my invention is ,to provide a transmitter whereby an on 1 orator can send a. signal to any ono of a number ofrtkeiVing stations to llw exclusion of the others. v

A secondary ohj'eul is to provide means \i'hervhy tho rotating parts at the aeveral r0 l relying stations and at the transmitting stal thin air automatioally sym'hronimzd or kept in step during the usual operation of tho; amiaratus without any spm ial act of the: operator, although said rotating parts may. i if desired. hoall not to zero position or synl (-hronized hv a sfpouial oporation as hoi'e inai'ter more hilly descrihvd.

ln tho drawings which avoompany and l lorm a part of this sporitiration. l havol shown onv arrangmnwl of apparatus and vim-nits whorohy tho loragoing ohjorls may I .hootl'oi-hal: although it will ho undorslood that many moditir-ations may ho madr by those skilled in tho art hoth in the a )Mlllltun-and in thoa-irmiit arrangements without departing trom' tho prinoiple of my invontion'.

:li1 thedrawings, lligurp 1 is a diagram shown in Fig l Fig. 3 is a diagram of one form of transmitting system that ll'lil vl lit omploy l with ..hi I'm-hiring system illus-- rated in Fl 1: Fig. l is an i-levatioii of. a portion ot ythv apparatus at tho tranamilting station": Fig. 5 is a plan riow ot'lluapparatus shown in Fig. 4-. and Fig. (l a diagram showing the (lHllllH ot a oomploto f system.

In order to mo'rvv fully disuloso my inron an elevation at a portion of the apparatus l --tion, 'I have shown in Figs. 1 and'Q. om"

form of receiving npparatiis that may be: employed 111 connection with my improved 1 is liridgod ar-ro latonted Fol). 18. 1913.

Divided and this application filed October 7,

' ll'tlllhlllllltl'. In Fig. 1. a polarized magnet.

45 tho line I l between the po nts 11. I) and is arranged to actuate the armaturo L wlnr-h pivoted at Q and (111' rim tho vst-apo may ho tll'lVlll as tho spring:

moot whorl l with which meat 3. l The shaft 5 which by any suitable motor, such motor it, carries -tho escapethe escapon'iont 3 roiipvratos. the toothvd wheel T and the vontart arm ll onomore tooth 'lho esvapement wheel has than the wheel 7, one of the trot-h ol (hi latter having been omitted, as

shown at 9. at silo the atop-a1 whorl. 'lho a: at 10' and pro magma! 13 am a point diametrically opponi 8 which is carried by said -matm-v in which is pivoted \idvd with the yoke 10", is

. arrangod in he ost-illalod 'hy the polarized l rari'ivs at one end of its who a wlwvharri-slinn (lotion slK'll as the prst .11. and a (low-o. such as opmato wiih tl of tho whrul 7.

also hr rarrivd yoke and is an contort arm 14 t tho othor a, wheol-lockh1g tho tooth 12 arranged to oo- 10 nolvhes hotwoon the teeth 'lho (contact point 13 may by and insulated from the ang ed to (-ooporato with tho 'lhv vontai-t arm 14 is oonnvotod with ou Sltltl of tho lino at the point a in any suitahlo llllllllltl'. as f r oxamplv hy the hruxh' lfi who-h makr-s roolavt with the shaft 5 a shown in tho lll' omlorritooil who'll rarrioa durt iroly vomit pros-out vasv. although it "ill in prartivo that tho framo tho said shaft will ho 0onw-tvd to our side of tho lino.

as at tho point w. The circuit containing tho rw-riring Hlilill 'H] signaling apparatus may ho voimorfod lNtWtPH tho other nido of tho lino as at lho point am 131. la Fig.1 s: as a polaiizvd point 1/ and tho ronlavl point 1 tho vomlvnaor l 'lho oporatio ax follow I lla prorirlod with shown in lfig.

l the vontavt point iid signal holl vonoorlod hvlwoen tho 1 hroogh n of tiuroroirionf system is (-h ror'viving station will he lllPill'tllllS idonlir-al with that: l and tho oonlacl arms; 14

will lN' :i'rramti-rlr i n s urrt-ssivo positions around tho viu'limlormi -i ol' the toothed whorl 7 so that silo a dillurvnt rat'li a'rm is arranged oppoono of the notfhQS, that is to l. for oxam ilo, may have its arm l-l arrangrd ()lipu lll the first. notch w from the doubl e notch t QtatioaNQQJnay a pparatus is shown i by step rotation of the wheel 7 until the arm 14, rigidlycarried by the shaft to which said wheel is connected, comes opposite the contact point 13, whereupon a pulsation ofcurrent opposite in polarity to those which effected the rotation of the wheel 7, is trans mitted to energize the magnet 15 thereby bringing the point 13 into contact with the 1 arm 14 to close the circuit between the points a and d and actuatethe local signaling apparatus 19, and placing the tooth 12 in one of the notches to lock the wheel against further rotation. Assuming that the armature 2 is in the position shown, a current impulse of one polarity will cause the magnet 1 to attract the righthand end of the armature. and at the same time charge the condenser 17. Simultaneously, said impulse will energize the polarized magnet 15 and cause the armature 10 to to e the position shown, the contact point 13 being out ofcontact with the arm 14c and the post 11 being in its wheel-arresting position in the path of thestop-arm 8. As soon as said impulse ceases, the condenser discharges through the magnets 1 and 15, suchndischarge through the magnet 1 being opposite to the original direction of current flowing therethrough, so that the lefthand side of the armature is again attracted. However. the direction of the condenser discharge. through the magnet l5 is the same as that of-the original current flow therethroulgh, so athat the position of the armature 10 is not altered. The solid arrows in Fig. 1 indicate the direction of flow of said current impulse through the magnets andthe dotted arrows thedirection of the condenser discharge therethrough. causes the wheel 7 to rotate past the tooth 12 to the extent of one notch, said tooth always being opposite a notch when'the magnet is deenergized, or in other words, when the armature 2 is in the position shown. Thus, it the train-clespatcher de-- sires to call the station numbered five, he will transmitfive, current impulsesl f: a given polarity, (assuming of course that each wheel has been set to zero) so as to bring the contact arm 14: at station 5 but at no other station, opposite the tooth;

and Eontact point 13. He will then The signal impulse 5 thereby bringing the stop-arm directly oppo-- The operator may now transmit a number of current impulses of said opposite p0.- larity for the purpose of actuating the polarized bell 19 or other local signal device.

It will he understood of course that each magnet 15 at all the stations will operate the arniatures 10 in the manner above set forth and that lheteeth 12 will; arrest the further rotation of all the wheels 7. but inasmuch as the contact arms 14- are arranged as above described. none of the local signaling apparatus will be actuated at the other stations. Upon the sending of an impulse or impulses in the original direction, the armature 10 is again moved to the position shown in Fig. 1 by the cnergization of the magnet 15, the tooth 12 is thereby disengagcd froi'n its locking position, and the armature 2 is again oscillated in the manner set forth.

'To set the toothed wheel 7 at Zero with .the center of the notch ll opposite the tooth l2 and the stop-arm 8 against the post 11. the operator zit-the transmitting; Stfit10n-W1H send over the line pulsations in the original direction (shown by the solid arrow) equal in number'to the number of teeth on the wheel 7. thereby bringing every stop-ar1n flfi n it co perating atop-post. He will then send over the line oncpulsation in the direction of the solid feathered I arrows. whereupon each stop-arm will beilreleased in the following manner: Such i'cversedpulsation will pass through the magnets 1 in the direct-ion of the solidi-feathered. arrow when; the armature is inf-the "positioii lshown in Fig. 1. so that said armature willllnot} be oscillated. and said pulsation wi' "pass through the magnet. 15 in the direction of the solid feathered arrow so, that disarmaturc 10 will be attracted to, the left, thereby moving the postll toits releasing position.

out of the patl pt the stop-arm and the tooth 12 into the notch 9. ,When said reversed pulsation cesses, the condenser 1'? discharges in the direction oi the dotted feathcred arrow which direction isthe same as the original current impulse) so that the armature is oscillated and. the Wheel? stepped around a space equal to one notch.

owsm'iii one current impulse of the "'oppo- 1 site the post, this movement of the wheel w h the result that the cur- 2 being permitted by the double notch '9. The

' ity, such reversed current impulse being; for

' thus sent over the lino other "words, thr stop arzn 8 al the transmitnocaase condenser discharge asses through the magnet 15 in the same irection as the reversed impulse, so that thearmatnre 10 is not moved back to the right. An impulse is in the original direction. oscillating the armature 2 and throwing the armature it) over to the right in the position jshown in Fig. 1. The cessation of this impulse will then cause the wheel to movc half a notch farther, so that one pulsation will now cause the contact arm l-t of station 1 to come opposite the contact point 13. two pulsations will cause said'arm to come opposite said point at station and so on.

'lhotransmitting station will be provided with an apparatus similar to that shown in Fig. 1, but provided with means for anti uiatically sending over the linc any desired number of impulses of a given polarity followed by one impulse of the opposite polar the purposc of placing each post It in its releasing position and enabling each stop l arm to pass the samc. For instance. with the apparatus set in the position shown in i Fig. l. in which the arm 14- of station to is opposite the contact. point til. it will be obvious that four pulsations of current will cause all the stop-arms 8 to come in contact with their respective posts. so that were a reversed current impulse not sent at the cud of four direct current impulscs. the motion of all the wheels would be arrested. The sending of this rovcrsed current impulse will not actuate. any local signal appaiz-itus. for the reason. as above explained. that no contact arm ll is hvrated oppositc the notch 9. Thus it any wheel or wheels is out of step with the rcst. thc t'u'dinary operation of the apparatus for signaling will automaticatty et 'cct the synchronization of the stopby-stcp rotatin, parts once during every revolution and a small fraction thereof,--inv ting: station cannot pass the post it at, said tation twi e successively without ctl'ecting: thc complete svra'hronization or thc setting: to act-o ot' all the whccls T.

In apparatus of this kind where a number of widely separated stcp-by-stcp nicchanisms are cmployed, it is ot' coursc necessary to cmploy synchronixcrs. and so tar as I am awarc. the synchronization of such parts has hcrototort; always horn ctl'cctcd by a special apparatus requiring a special operation on the part mt an attcndunt. ll will thcrci'orc be seen that. the automatic svnchronizution of the several toothcd wheels forms a salient tcatlu-e oi my invention.

The present system is intruded for use, ovcr a relatively longline. about two hunrlt'od miles in length comprising a number of receiving stations (shown in the present n stance as forty-cigl'itl and therefore I prcnr t tit), to thcv line,

to employ polarized magnets in all instances because of thc wcll known sensitiveness of in Fi ;l 33 re )rcscnts a suitable source of electric cncrgy connected normally through the hold-back nutgnct ill. contact .55), and armature 514. so that the armatures ltl. '37 of the vibrator magnet, 35 which by their fiill'illg'fitlpptll'lt-i 43. Eli are held away from their ('(It lptl'tltlllg contacts it). H are attracted and held back against vibration until the magnet i-l-l is deiiuergized. 5t; represents u manually-operated contact member or plunger provided with an insulated hcad 57 and carrying the contact 58 which is connected to one side of the battery at j. it will be understood that. the transmitting apparatus will be provided with as many plungcrs as there are receiving stat-ions. al' though for convenience only one has been shown in Fig. 3. Whcn the plunger is pushed inward. the contact piece 58 engages the spring contact member 5t thereby closing the circuit of the vibrator magnet- 35 throughthe battery by way of the point. f. through the spring 38, contact 39, windings of the nmgnct. 35, spring 59, contact piece .38, point thence back to.t.he battery. and also closing the circuit of the starting magnet. 5! through the battery by way of the point r windings of the magnet 51, spring 59, contact. piece 58, point thence back to the battery. The cncrgizution ot' the starting magnet closes the circuit of the condenser (it, bridged across the line L L between the points A: and Z, through the armature 54 and contact 55, and-at the same time opens the circuit of the hold-back magnct B-t between the armature 52 audits cooperating contact: 52-3. The arniat'ures 3t: and 37, avhich may be mechanitmlly c0nncctcd, are now set in vibration and pulsat-j int: currents are sent over tho line by way of contact 40, armttturr 13 of the receiving rota-y 42. contact 50. against which said arnmturc normally is held. impedance coils and back through. the impcdaiicc coils tit), contact 48, against which the armature ll noru'ullly is held. contact 4-1, and armature will, the circuit being complotrd through the battery by way of the oin. l1 and thence to the armature 37 of the ed across the line.

vibrator magnet and contact 40 by Way of the point The shaft 5 at the transmitting station carries apparatus identical, except for the" omission of the contact point 13, with't-ha-t carried by the shatt- 5 at each receiving sta tion, and is governed by a magnetically operated escap-ement in the aaine way as the receivingstation apparatus. the control magnets for said escapement heingconnect- The "contact arm 14: at the transmitting station is arranged to make contact with, and to have its motion arrested by. a plunger 56 when the same is comspring 59, but not. sutticiently't-o cause the end of the plunger to engage the contact arm 1%. the ulsatin currents which are sent out over the line in the direction of the solid arrow shown the wheels 7 to rotate until the movement thereof is arrested by the stop-arms 8 coming into contact with t-heirrespective posts '1]. soon as the stop arm 8 at the transmitting station engages the post 11.. the

circuit through the reversing relay is closed through the battery by way of points f, windings of magnet 42. point m. shaft; 5. arm 8, post 11'. and} thence back to lthe battery by way ol the? point '1'. The energi'zation of the lnagnetl lil causes the amiatures 43. ll to be thrown over to currentreversing position against the contacts 4 7. ll respectively. thereby sending-one pulsation of reversed current over the line. which aetuates all the magnets 15 including the one at thetransmitting station, so that, as above-described in connection with Fig. 1, each post is moved to the left to its releasing position so as to permit the stop-arms to move past the posts.

After the contact between 8 and 11 is broken, the reversing relay is held in currentreversing position by the by-path m 46 45 41 36 /z. and is not deenergized by the opening of the contact between the post 41 and the armature 36 until shortly after the breaking of the contact between 8 and ll.

intermittent, currents. 'hen the armature 3? makes contact with the post 40, a current in Fig. 1, cause all.

with 3, the flow of current to the line is interrupted and the discharge oft-he condenser 17 causes the armatureQto take its other position. The armature 36 vibrates synchronously with armature 37 and the apparatus is so arranged that when armature 37 is out of contact with post 40, thearm 8 is in contactwith post 11. As the armatures 36 and 37 vibrate synchronously it follows that when armature 37 is out 015 contact post 40, armature 36 is out of contact with post 41. The next impulse sent, to line by armature 37 contacting with post 40 will cause arm 8' to leave the post 11, and inasmuch as the armatures 36 and '37 vibrate synchronously, it follows that the'armature 36 is in contact with the post 41 when the arm S lea'vesthe' post .11. Therefore the reversing relay is held in current-reversing position by said lay-path and is'not de'e'nen,

gized by the opening of said by-pathbe-. tween the armature 36 and post e1 until shortly after the breaking of the eontactbetween arm.8 and post 11, so that a combeen deenergized. current pulsatidns in the original direction are again sentover the line, thereby causing the wheels 7 tocontinue their step-by 'step rotation. To set all 0 th wheels at zero; the transmitting operaill thereforedepress any one of the plu' gers 56 until the contact arm 8 has passed the post 11" and the Wheel 7 at his s tation has made a revolution and a 10 fraction thereof. In view of what has heretofore been said in regard to automatic svnchronizalion, it will be understood that the special synchronizing operation just described will be but rarely necessary.

To call any given receiving station, the operator depresses the corresponding plunger 5G to its full extent, the contact piece 58 passing over, but still remaining in contact with, the spring 59,. so that Without 115 breaking contact with the spring; 59, its inner end is in the path of the arm 14. As soon as the motion of the wheel 7 at the transmitting: station is arrested by the arm ll striking the end of the plunger 56. the 12:;

,cireuit. oi the reversingrelay is closed.

through the battery by way of the points of. '1 winding of the magnet 42. point m. shaft lh'e magnets l of the step-by-step apparatus which'carry the arms a 8' are energized by rent pulsations are sent-overthe line until impulse is sent to line and causes the armal ture'Q totake a certain'position. hen the stationi's thrownover tattle-left (fronrthe the plunger is withdrawn, with the result. that every armature 10 at every receiving armature 37-is in the posit-ion shown in Fig. position; shownin; Fig. need the contact 3336 point 13 at the particular station called is brought against the contact arm'lt at said station, thereby actuating the local Slgllill apparatus in the manner heretofore dc" 3 point 1;}

scribed. It will be noted that when the wheels 7 are all in step, all the stop-arms S will come against their respective posts 1] at the same instant, and that the reversed current impulse sent out as above described by the contact formed between S and 11 will move each post out of the path of its cooperating stop-arm, so that the movement. of the wheels is nevermore than momentarily arrested, but in cases where a wheel is out of step with the other wheels, the movement of the wheel in question is arrested one or more times until it is brought into step with the others.

When the reversing relay is energized and the armature l4 thrown over against its contact point at), the spring contact 453 is brought against the post 46, thereby closing the by-path above referred to Whichrompletes the circuit of the reversing relay by Way of the contact 41 and armature 36, and kee )8 said relay energized for the enceed ingly short interval of time between the breaking of the contact of the plunger with the arm l i and the breaking of the contact of the contact piece 58 with the spring 59, so that every time a plunger is withdrawn, the last impulse sent over the line will be a reversed current impulse and the armature f. at every station will be in the position shown at Fig. 1. If this by-path were not formed, the reversing relay would be dei-inergized as soon as the plunger broke contact with the arm 14:, and a partial direct impulse would transmitting apparatus shown in Fig. '1.

be transmitted to the line before the contact piece 58 was withdrawn from cngagen'icnt with the spring 59.

It will be noted that by means of the the step-by-step rotating parts of all the stations automatically are ynchronizcd dur ing the operation of the apparatus in its intended manner without requiring any special synchronizing operation on the part of the operator.

The function of the ciiuidenser ill abridged across the line by the energization of the starting relay 51, is merely the usual function or such condenser to prevent sparlc ing at the contacts between it? and 4.0, and 38 and 39. lrVhen a station has been called and the plunger withdrawn, the magnet 51 is de'c nergizcd and the tamdcnser disconnected so as not to reduce the elliciency ol' the line for the transi-nission of telephone currents. The in'ipeilance coils (it), (31'. which may be employed, pcrforn'i the usual function of smocthin; out the pulsations In Figs. 4- and 5,1 have shown the stepby-step mechanism for the transmitting station which has been indicated diagram:

l l l matically in Fig. 8, it being understood of course that there will be one plunger 56 for every receiving station associated with the With the exception of the contact and the connection of the stop post 11 to the battery at the point i, the step-bystep mechanism at the transmitting station is identical with those at the receiving stirtion.

In Fig. 6 l have shown the circuits of a con'iplete system including the transn'iitting station and two receiving stations bridged across the main line, the same reference characters as in the other figures being employcd sothat Fig. 6 will readily be understood from the detailed. description of the other figures. I

This application is a division of my application Serial No. 561,615, filed May 16, 1910..

Although I have described my invention with some particularityas applied to a telephone system, it will readily be understood that it is not limited to such application and that it may be applied to any system where in the selective control of'rotating members by a distantly-located transmitter is required.

I claim:

fl. In a selective sigimling system. a transmitting apparatus comprising a source of pulsating current, a rotatable contact member, means controlled by current impulses oi." a given polarity for imparting a step-bystep rotation thereto, arresting-n'ieans for' loo stopping the rotation of said member at a given point, and means controlled by said arrcsting-n'icans for causing said apparatus to transmit a current impulse of the oppw site polarity.

2. in a selective signaling system, a transmitting apparatus comprising a source of pulsating current, a. rotatable contact member, means controlled by current in'ipulscs of a given polarity for imparting a step-bystep relation thereto, arresting-mcans for stopping the rotation of said member at a given point, means controlled by said ar-. restingducans for causing said apparatus to transmit a current impulse of the oppcsite polarity and a magnetic control device for said arrestiug-mcans, said magnetic control device being constructed and arranged to be actuated by said current impulse of opposite polarity for moving said arrestingmeans to relcasirig-position.

3. In a selective signaling system, a transmitting apparatus comprising a source of pulsating current, a rotatable contact mem ber, means cmitrolled by current impulses of a given polarity for imparting a slept-by step rotation thereto, a reversing relay associated .with said source of pulsating current, arresting mcans for stopping the re tation of said member at a given noint a nd as incense menus controlled by said arresting-moons ror causing said reversing relay to reverse the polarity of the current impulses trans mitted.

. 4c. In a selective signaling system, a transmitting apparatus comprising a, source of pulsating-current, a rotatable contact member, means controlled by current impulses of a given polarity for imparting e step-by step rotation thereto, :1 reversing relay associnted with said source of pulsating cur rent, arresting-means for stopping the retation of said member at o given point,

,means controlled by said arresting-moons for causing said reversing relay to reverse the polarity of the current impulses transmitted, and a magnetic control device for said errestin'gmieans, said magnetic control device'being constructed end arranged to be actuated by a current impulse of the opposite polarity for moving said arrestingmeans to releasing osition.

5. In a selective signaling system, u trons mitting apparatus comprising a source of pulsating current, a rotatable contact member, means controlled by current impulses of a given polarity for importing" a step-bystep rotation thereto, a reversing relay elsso' impulses of a given polarity for imparting step-by-stcp rotation to said cont-actmembet, a reversing switch arranged to reverse the polarity of the transmitted impulses, a magnetic control device for said reversing switch, and means associated. with said rotatable contact member for controlling said nmgnetic control device.

7. in a selective signaling system, a tiilfiS' xnitting apparatus comprising a source oi directcurrent, an electromagnetic currentiuterrupter associated therewith, a rotatable contact member, means controlled by current impulses of a given polarity for importing step-by-step rotation to said contact membeer a reversin switch arren ed to reverse the polarity of the transmitted impulses, a magnetic control device for said reversing switch, means associated with said rotatable contact member for controlling said insignetic coutroldevice, and means independent ,ol said rotatable contact member for rosin teining seid reversing switch in current-revol-sing position until a complete impulse of opposite nolerity has been transmitted.

8. in a. selective signsiling system, a transmitting "apparatus comprising a source of direct current, an electromagnetic currentinterrupter associated therewith, a rotatable contact member, means controlled by current impulses of a given polarity for imparting step-byetep rotation to said. contact member, a reversing switch arranged to reverse the polarity of the transmitted impulses, u magnetic control device for said reversing switch, means associated with said rotatable contact member for controlling said mugnetic control device, e by-path independent of said rotatable contact member, and u sup plemental contact for said reversing switcl's arranged, when said switch is in current re versing position. to close the circuit of said magnetic control device through said by path.

; In a selective signsling system,u transmitting aopuretus comprlsmg a source (iii direct current, an electromagnetic current interrupter associated therewitjh, a rotatable" contact member, means controlled by current. impulses of a given polarity for imparting step-by-step rotation to said contact member, a reversing svitch arranged to reverse the polarity of the transmitted impulses,'a magnetic control device for said reversing switch, means associated with said rotatable cont-act member for controlling said magnetic control device, a by-path independent of said rotatable contact member, a. supplemental contact for said reversing switch ar ranged, when said switch is in current 1evcrsing position, to close the circuit. of said magnetic control device through said by path and a, contact arranged to be opened by said currentinterrupter for opening said bypath and thereby definergizing said magnetic control device,

10. in a selective signaling system, a transmitting; apparatus comprising a source of pulsating current, a rotatable contact member, means controlled by current impulses of given polarity for importing a step-by step rotation thereto, a reversing. relay associuted with said source of pulsating current. a manuallvo 'ieruted contact member adapt ed to cooperate with said rotatable contact member, and a circuit tlufougxlrsaid rovers ingr relay arranged to be closed by said con tact members and thereby cause current impulses of the opposite polarity to be trnnsmilled.

11. In a selective signaling system, a transmitting epigarutus conu'u'ising a source of direct current, an electromagnetic currentinterrupter associated therewith, a rotatable contact member, means controlled by current impulses of e given polarity for imparting s etenbyetep rotetion to said contact memlit) her, a reversing switch arranged to reverse l membe the polarity of the transnntted impulses. a tatable said reversing magnetic control device arranged to be closed by said contact members and thereby cause current impulses ot' the opposite polarity to be transmitted.

12. In a selective signaling system, a transmitting apparatus comprising a source of direct current, an electromagnetic currentinterrupter associated therewith, a rotatable contact member. means controlled by current impulses of a given polarity for imparting a step-by-step rotation to said contact member, a mannally-opcrated contact member adapted to cooperate with said rotatable contact member, a circuit through said current-intcrrupter, amt means whereby said circuit is closed by said manually-operated contact member before the cooperation of the latter with said rotatable contact member.

13.111 a selective signaling system, a transmitting apparatus comprising a source of direct current. an clcctromagnctic currentintcrruptcr associated therewith. a rotatable contact member. means controlled by current impulses ot' a given polarity for imparting ste rltv-step rotation to said contact member. a normally energized holding-mag net for said current-interrupter, a manuallyoperated conta t member adapted to cooperate with said rotatable contact member, and means controlled by said manually-operated contact member for deenergiziug said holdinganagnet before the cooperation of said manualIy-operated contact number with said rotatable contact member.

it. in a selective signaling system. a transmitting apparatus comprising a source oi direct current. an electromagnetic current-intcrruptcr associated therewith. a rotatable contact number. uu-ans coutrollcd'by current impulses ot' a given polarity for imparting a stcp-b \'-step rotation to said contact member. a holdingauagnct for said current-interrnptcr. a normally dci ncrgizcd tartinganagnet. an armature for said starting-magnet. a circuit including said source ot direct current malty closed by I the armature oi said startmganagnct. a

mannallywrwrated .contact a manually-operated cont-act memand lmldin-ganagnct nor- 1 adapted to coiiperatc with said rocontactfinember and means controlled by said inaimalty-operated contact member for energizing said starting-magnet and thereby breaking the circuit of said holding-magnet.

15.111 a selective signaling system, a transmitting apparatus comprising a source of direct current, an electromagnet currentinterrupter associated therewith, a rotatable contact member, means controlled by current impulses of a given polarity for imparting a step-by-step rotation to said contact; member, a manually-operated contact? member adapted to cooperate with said rotatable contact member, a condenser and means controlled by said mamially-operated contact member for connecting sald c0ndenser across the contacts of said currentinterrnpter.

16.111 :1 selective signaling system, a transmit-ting apparatus comprising a source of pulsating current, a rotatable contact member, means controlled by current impulses of a given polarity for imparting a step-by-step rotation thereto, a reverslng relay, a plurality of manual y-operated contact members each adapted to cooperate with said rotatable contact member, and a circuit through said reversing relay adapted to be closed by the cooperation of said rotatable contact mci'nber with any one of said mannally-operatcd contact. members and thereby cause current impulses ot' the opposite polarity to be trausn'iitted.

17.111 a selective signaling system, a transmitting apparatus comprising a source of direct current, an electromagnetic current-interrupter associated therewith, a rotatable contact member. means controlled by current impulses t'or impart-in" step-by-step rotation to said contact mcn'ilier. a reversing mechanism arranged to reverse the polarity of the transmitted impulses, a magnetic control device for said reversing mechanism, and means associated with said rotatable contact member for controlling said magnetic control device.

in testimony whereof, I have hereunto subsrribed my name this 21st day of Sept. 1910.

VERNON DITRBIN. Witnesses: 

